On the heels of more grim unemployment news, President-elect Barack Obama yesterday offered the first glimpse of what would be the largest public works program since President Dwight D. Eisenhower created the federal interstate system in the 1950s.

Obama said the massive government spending program he proposes to lift the country out of economic recession will include a renewed effort to make public buildings energy-efficient, rebuild the nation’s highways, renovate aging schools and install computers in classrooms, extend high-speed Internet to underserved areas and modernize hospitals by giving them access to electronic medical records.

“We need to act with the urgency this moment demands to save or create at least 2 1/2 million jobs so that the nearly 2 million Americans who’ve lost them know that they have a future,” Obama said in his weekly address, broadcast on the radio and the Internet.

Obama offered few details and no cost estimate for the investment in public infrastructure. But it is intended to be part of a broader effort to stimulate economic activity that will also include tax cuts for middle-class Americans and direct aid to state governments to forestall layoffs as programs shrink.

House Speaker Nancy Pelosi (D-Calif.) has called for spending between $400 billion and $500 billion on the overall package. Some Senate Democrats and other economists have suggested spending even more — potentially $1 trillion — in the hope of jolting the economy into shape more quickly.